Numerous types of ice skate sharpening machines have been proposed, and fall into two categories which are floor mounted hand operated machines and floor mounted automatic coin operated machines. The hand operated machines are generally heavy and require much craftmanship to operate, also, in most cases, questionable results are obtained mainly due to the mechanism of the machine itself and the ability of the operator. The floor mounted automatic coin operated machines are heavy, complex and expensive. These automatic machines provide poor sharpening results, this is due to the mechanism of the machine itself.
The blades of hockey ice skates require different radius of concavity depending on the weight of the hockey player. This radius of concavity can be obtained only if precision is built into the machine.
In known ice skate sharpening machines, the object is to have the grindstone to be as much as possible in line with the skate blade so that the radius of convexity of the grindstone forms the intended radius of concavity along the skate blade. These machines do not provide against the effect of the position of the grindstone dressing mechanism with respect to the skate blade central axis, and also they do not provide against the effect of the means for clamping the blade with respect to the thickness of the blade. Hockey skates, figure skates, goalkeeper skates and racing skates have all different thicknesses. Many attempts have been made to have blade clamping means that would hold the central axis of the blade directly in line with the grindstone central axis but poor results have been obtained because proposed blade clamping means always include a fixed side against which a moving side is squeezed. It can easily be seen that for different blade thicknesses, the central axis of the blade is thrown off.
Even worst, since the sharpening diamond is not in line and cannot be in line with the skate blade clamping means then the end result is a blade which has a high edge and a low edge. These above described statements are true for both the hand operated and automatic coin operated machines.
Hand operated machines alter the blade radius of curvature of new skates because of the uneven pressure applied by the grindstone when the blade is applied against it by the operator. This operation produces a light depression in the middle of the blade.
For the sharpening of figure skates, there is one important criteria to respect, the sharpening of the blade end must be square and sharp which means that the grindstone must not terminate its motion at the rear portion of the blade according to a curve. Hand operated machines do not meet this condition although some operators use a mechanical template to meet this square and sharp end condition but the set up is so lengthy that once it is set, it is used exclusively for figure skates. Automatic coin operated machines do not meet the square and sharp end condition, the end of the blade is rounded by the grindstone as it is for the hockey skates.
It must be noted that the problem of centering a figure skating blade directly in line with the grindstone is the same as it is for a hockey skate. The same applies for the radius of concavity where the hand operated sharpening machines have a range of selection with a poor accuracy whereas automatic coin operated machines have only one radius of concavity which is generally 0.75 radius.
It is difficult to accurately and efficiently sharpening the grindstone for both manual and automatic operated machines. For manual operated machines, the sharpening of the grindstone according to a selected radius of concavity is tideous because the sharpening diamond is integrated on a shaft with a cone end which generally slides in a hole. Thus, by pulling it out or in, a maximum or a minimum radius of concavity is obtained. However, when the sharpening of the grindstone is actually performed, the manual mechanical advance of the diamond is usually not done with great precision so that, instead of having only the diamond point touching the sharpening surface of the grindstone, a part of the cone touches the sharpening surface at the beginning of a sharpening cycle before that the diamond point touches the grindstone.
Also, it happens frequently that the operator drives the diamond too much into the sharpening surface of the grindstone so that grinding particles are emitted in every directions, this result produces a health hazard for the lungs of the operator.
Automatic coin operated machines have different problems since only one radius of convexity is given and this is generally 0.75 radius. The sharpening of the grindstone is controlled mechanically and electronically. The mechanical assembly is generally a yoke with a diamond in the center, the diamond describing an arc on the sharpening surface of the grindstone. When the grindstone is worn to a point where the diamond does not touch the grindstone, the machine is automatically stopped, a light indicates to the operator that it is time to adjust the diamond position. As far as dust particles are concerned, most automatic machines have a vacuum to collect grinding particles.
Both manual and automatic machines accept hockey and figure skates but they are not designed for goalkeeper skates, long blade skates and racing skates.
The general public is more demanding when their skates are sharpened, especially when expensive skates are concerned, they do not want too much material being ground off their blade. Also, a preselected radius of concavity is required.
The hockey player would like to have a very personalized skate sharpening with a radius of concavity selected with respect to his weight. The figure skater would like to have his skate sharpened with a selected radius of concavity, and with a sharp and square end. The hockey goalkeeper would like to have his skate with a radius of concavity of at least 3/4 of an inch. The race skater has to sharpen his skate himself because existing sharpening machines cannot perform the job.
Hand operated machines can generally provide a variety of radius of concavity but the limitations are that the radius of concavity is not aligned with the central longitudinal axis of the blade because the sharpening diamond is not aligned with respect to the skate blade clamping mechanism which is itself limited by its design of having a fixed side onto which a moving side is squeezed. This design does not allow a variation of the blade thickness. In the case of figure skate, the chrome deposit is uneven and the thickness of this kind of skate can vary substantially from one end of the blade to the other. Therefore, the end result of having good sharpened skates depends entirely on the ability and craftmanship of the operator.
For a figure skate, the blade is sharpened in a similar manner as it is for a hockey skate, as a result, the end portion of the figure skate is rounded and not sharp and square as it is supposed to be. The reason for this resides in the fact that the special set up required to obtain the square and sharp end, is difficult to install.
Goalkeepers whether they like it or not, do have a radius of concavity on their blade which is generally large in order to minimize the radius effect and this is because the grindstone cannot be sharpened in a flat manner due to the mechanism of the machine itself. Automatic coin operated machines have only one radius of concavity which is generally 0.75 radius, and the diamond is not aligned with the blade clamping mechanism which produces high and low edges on the sharpened blade.
An object of the present invention is to provide an apparatus for sharpening the blade of a skate with more precision than the one obtained with the apparatus known in the art.